Initially the geth will not have detected you, so you can quickly position your squad behind cover and prepare for the Shock Trooper rush. Use the piece of cover near the door to your advantage, along the explosive crates laying around, to take down the attacking geth. Once they all fall, Matsuo will enter with a few guards and question Shepard about the incident. Once the conversation is finished, Matsuo will leave and you are free to take the Mako at the end of the garage to Peak 15. There is an upgrade kit near the M29 vehicle.

If you want to make this fight easier, you can unlock the M29 Grizzly’s cannon and use it to your advantage. However, this will result in fewer experience points. You could defeat most of the geth first, unlock the Grizzly for experience points, then exit it and finish off the geth. You cannot access the Grizzly after the fight.

Note: This is the last convenient opportunity to switch out squadmates through the Normandy, while you're still relatively near the ship. You can technically do so further down the mission, but the distances involved will make for a tedious trip back.

Once you leave a notification will come up that you have entered a Level 1 Cold Hazard; the landing party will need to limit their exposure outside the vehicle during the drive to Peak 15. This ride will not be uneventful, but is relatively easy. Just don't fall off the edge!

Head out of the garage and down the path. Eventually you will run across a wrecked Grizzly with a crate beside it. Continue along the path and you will approach the first tunnel. The geth have placed a turret here, which is reinforced with Geth Shock Troopers, Geth Rocket Troopers, and Geth Troopers. In addition, the geth have deployed personal shields near their positions. There is another wrecked Grizzly here, with a crate and a medical kit beside it.

About halfway down the tunnel are four Geth Rocket Troopers. They all typically shoot at the same time so it makes their shots easy to dodge. Once the four Rocket Troopers are permanently deactivated, get out, if you haven't already, then grab the two upgrade kits that are on the ground; one rests on either side of the tunnel.

When you head down the tunnel, a cutscene will play, showing a Geth Armature on the road to your destination. It also has some Rocket Trooper friends. Take out the Rocket Troopers then focus on the Armature. There are two crates requiring Easy Decryption beside the burning Grizzly.

Move on until you reach the next tunnel, which is defended by more geth. Outside the tunnel exit is a med kit, which will prove useful.

Tip: While you are at the end of the earlier tunnel, some of the geth at the second tunnel might notice you and start firing at the Mako. If you wait on your side of the chasm, they will walk directly at you and end up falling into the chasm.

The only enemies from here to the Peak 15 research facility are three Geth Turrets. The first one is around the corner and at the next U-turn. The second is about halfway down the path from the first to the final turn. The third is above and to the left, on the mountain, of the Peak 15 garage door. Once you are done, save, and enter Peak 15.

Note: There is a possibility that you can’t save the game. Move around until you do because the garage has some enemies in it.

Before you enter the garage you will want to save your game as there are very few Auto-Save points here. As you enter the garage, the cold hazard will disappear when you enter the first room. When you move through the large door into the next room, get in cover quickly because you will come under fire. The large room beyond holds a Geth Juggernaut, a Geth Destroyer, a Geth Shock Trooper, and a very annoying Geth Repair Drone. There are also three krogan, two on the floor in the back, the other on the catwalk above and to the left.

Take out the repair drone as soon as possible because it will repair the geth you are trying to destroy. The geth will come straight after you, so you will naturally end up concentrating on them first assuming you stay in cover near the entrance. When it makes sense, move forward and take the krogan down; just watch out for their dangerous charges when you approach their position.

The second the last enemy falls, the station’s VIMira comes over the intercom telling you of the amount of damage that the facility has sustained, in case that wasn't apparent. Before leaving the garage you'll find a crate requiring Average Decryption and an upgrade kit on the catwalk leading onwards. When you enter the security tunnels your squadmates will comment about the turrets facing the wrong way. Enter the security office near the elevator for an upgrade kit and a locker requiring Average Decryption, then take the elevator up.

Once you reach the top save your game and move on to the door. Inside is the cafeteria for the facility and it has some non-edible guests: geth. There are some Geth Troopers and a Geth Shock Trooper. There is little cover near your starting location, so move into the room if necessary while using abilities to keep the geth from concentrating too much fire on your squad while you take them out.

Your squadmates will comment about the damage and turning off the heat to kill anything that was released when all geth are down. Tip: Now would be the time to equip your toxic damage protection and anti-organic ammo.

When you get close to the stairs there will be a cutscene introducing a new enemy; a very large organic one at that too. Once you have control again, move away from the stairs because some explosive Rachni Workers will come charging down them. Take down the enemies because if they get near you, they explode and poison you at the same time.

Once the small rachni are dealt with, send your squadmates up first to have the two larger Rachni Soldiers focus on them; keep on the move to avoid their acid spittle which bypasses your shields. If you have biotic skills then use them because these large rachni are extremely vulnerable to physics-based attacks. A third Rachni Soldier will burst from a grate in the chamber at the top of the stairs when you approach.

Head down the corridor once they are all down. In the first room, you'll find a codex entry and a storage locker. Further down the hall you'll find a room with a medkit, but be careful as you exit because another large rachni will emerge suddenly. Kill it then head into the next elevator.

From the elevator, you emerge near the VI core of the station. As the door opens, another mob of Rachni Workers will approach from the other end of the room--take them out before they have a chance to explode all over you. Once they are down, one of your squadmates will comment that nearby is what appears to be a backup power system for the station's VI.

The main source of the outage at Peak 15 comes from the offline VI. When you get it back up and running, it will inform you of additional tasks to perform before you can move on: Noveria: Reconnect Landlines and Noveria: Reactor Repair. Each time you repair something, a Rachni Soldier will emerge from a grate to the left and on the far side of the room. Take it down and move on across the room.

Once you've got both the landlines and the reactor repaired, you're ready to head down the tunnel toward the tram. If you talk to Mira before proceeding, your journal will add the Noveria: Contamination mini-mission (if otherwise, it appears during the elevator ride to the tram). You'll find part of the tunnel ahead blocked and filled with rachni, so first go into the nearby office and grab the three crates in the room. Access the Mira terminal to figure out how to proceed. You have three options:

Ironically, the one that gives the most XP is the easiest, for once: repair the vents and watch the bugs burn, if your electronics skill is sufficient. As you leave the room make sure to turn around because the grate will pop up and another Rachni Soldier will emerge at point blank range. Take it down then head into the tunnel.

Open the door on the other side and four Rachni Workers will emerge: shoot them before they get too close.

You can now leave Central Station via tram and into the next area: Rift Station.

When your tram arrives there will be no enemies and only one way to proceed. Head around the corner and up the elevator to the Science Station, where you'll run into Captain Ventralis with a couple guards. You can ask him about the situation and what has been happening. They're on lockdown for a good while now, and are pretty serious in not letting anyone breach their tenuous security. When you end the conversation he will give you a pass card to the Hot Labs, an area which is back down the elevator behind you.

More rachni suddenly appear during the conversation. Take them out with Ventralis' help and then move on into the station. Alternatively, you can turn tail deeper into Rift Station and let Ventralis and his men take care of the problem. He notices this and will adjust his dialogue accordingly the next time you talk to him.

At this point you can do one of two things: follow the lead from Ventralis and head back down the elevator to the hot labs, or explore the main level behind him. If you do the latter, you may obtain additional considerations in getting to Benezia. This is important, because the story will unfold a bit differently for each decision. See Noveria: The Hot Labs if you wish to take Ventralis at his word.

In the main level mess hall/makeshift holdout you'll find several people you can talk to: Alestia Iallis, Petozi, Dr. Palon, and some other scientists and guards clearly chafing under the stress. Petozi the elcor merchant has a limited list of items for sale, though more usefully you can sell him anything that's clogging your inventory. On the right a door leads to the Guard Barracks - head inside and crack the storage and weapon lockers there (both on Easy Decryption).

There are three other doors on the left, when entering the mess hall. The first leads to the Quarantine and Barracks, the second leads down to the Medical Bay, the third leads to a sealed-off section of the base. Dr. Zev Cohen at the Med Bay requires assistance and will give you the Noveria: Quarantine mission if you accept. Wandering near the restricted area updates your journal with the Noveria: Rift Station entry. Be warned that hacking the door here will turn all the guards against you.

In any event, you will need to go to the Secure Lab marked on your map through any means necessary. See the aforementioned link for details.

Now, if you decided to pursue the lead at the Hot Labs before dealing with the business inside the Secure Lab, upon your return to the mess hall Ventralis surprises you with treachery, revealing himself and the entire security force to be under Benezia's employ.

They're all shielded and fairly clumped together at the mess hall, so crowd control talents will put them down quickly. You are also fairly exposed despite the presence of cover, so retreating back beyond the door you came in to whittle them down is a viable solution.

In this scenario, everyone in the facility is either out to kill you (the guards and drones) or absent (the other characters except Han Olar down at Quarantine and Barracks). If you mixed the cure for Thoros-B on Noveria: Quarantine, you can't return it to Dr. Cohen anymore. You obtain additional combat rewards in this manner but at the expense of NPC presence.

The Secure Lab is marked by the overhead sign sporting an Erlenmeyer flask. Warning: This is the final point of no return for the entire mission. Once you get inside, you'll be unable to backtrack and the mess hall will be forever locked out. Loot every crate you may have missed on the way, transact with Petozi one last time, if you must switch squadmates then take the long trip back to the Normandy, and finally, save.

Inside is Matriarch Benezia on an upper platform. You can talk to her and get a few questions answered. If you have Liara in your party, there are some words exchanged between mother and daughter. Once you are done Benezia will place the whole squad in Stasis while her Asari Commandos move into position. When you regain control you'll find yourself in the middle of what's arguably the most difficult battle in the game.

The entire battle with Benezia consists of 3 waves, with her dishing out biotic and pistol fire from her static position while her minions engage you in the catwalk-framed room. Benezia is invulnerable at this time, defeat all three waves to weaken her. Being caught in accumulated enemy biotics is never a good idea, and you'll be facing powerful ones here. Fortunately the structure of the room is such that you can easily identify places that block Benezia's attacks, giving you relatively safe positions for counterattacking the minions. Additionally, a bottomless pit rings the center of the room. Physics-based attacks biotic or otherwise pointed at the pit's general direction goes a long way in dispatching enemies.

The first wave consists of two Asari Commandos. They come directly in front of you. Don't let them unleash their biotics; disable them ASAP before getting the chance to pile you with disablers of their own.

The second wave consists of an Asari Commando and a Geth Sniper: 2 pairs. At this point you'll have familiarized yourself with the terrain and can move in whichever direction most advantageous to your style, then along comes the snipers' radar jamming. Consider equipping your most powerful detection upgrade on your weapons to counter it, as it will see continued usage later.

The third wave consists of 8 Geth Snipers divided into two groups. Benezia is visibly weakening at this point. If you move quickly you can often catch a group of four all in the same Singularity, Lift, etc.

Once they are all down you will begin another conversation with Benezia. She will start out defiant but her attitude changes quickly. Benezia says that the real threat is Sovereign and that Saren is just a tool. Ask questions and Benezia says that Saren sent her here to recover the location of the Mu Relay from the Rachni Queen. You can ask more questions, but eventually the indoctrination overpowers Benezia and she and three final Asari Commandos attack.

When the last enemy falls, a final dying conversation with Benezia occurs. When she passes, the mission entry is renamed into Noveria: Death of a Matriarch if you have some loose ends to tie up.

There's still the issue of the Rachni Queen in the tank the Matriarch was busying herself about earlier. Approach it and decide its fate; you can't get out of the lab while this is pending.

You've been battling inside the room before you can properly survey it, so if you haven't attempted to raid the crates during the boss fight now would be the time to do so. On the center platform near Benezia's corpse is a secure crate (average decryption). On the lower platform adjacent to it are two more secure crates (both average decryption).

If you haven't purged the remaining rachni yet, exit the Secure Lab and deal with them down at Noveria: The Hot Labs. This is completely optional, and the elevator down to Rift Station's main level is locked out anyway, so this is the only other possible loose end.

When you board the tram you automatically return to the briefing room of the Normandy. You can earn a few morality points for your conversation options and a few more depending on your conversation with the Council. The Council is frightened if you released the Queen, and admonishes you if you kill her, with the turian member asking you "Do you take pleasure in committing genocide, Shepard?"

On newer AMD CPUs, a bug may cause models in the game, including that of Shepard and the squad, to be rendered as blocks of black pixels upon entering the Peak 15 garage. This is caused by AMD discontinuing their 3DNow! support, and the game for purely relying on manufacturer check to enable 3DNow rendering.

There is also a mod that will fix this; it has the advantage of not having everything overly lit in Noveria.

According to Mass Effect's patch notes for version 1.02, the elevator bug that gets players stuck is fixed. There are some reports, however, that the fix doesn't appear to be working on some playthroughs.

If you use Singularity too early during the rachni fight following the first meeting with Captain Ventralis, one or both rachni may float downward into non-accessible areas and vanish. However, Ventralis and his men won't stand down because the rachni have not been killed. Saving and reloading can cause the rachni to burst out of the floor grates again, and will provide an opportunity to bypass this problem. Simply running out of the room and going about the mission also fixes the issue, albeit with Ventralis being displeased at Shepard's "help".

During the fight against Benezia, getting hit by biotic powers can ragdoll Shepard out of the catwalks and get you stuck or even killed. You can get out of this situation by ordering your remaining squad around to kill the enemies or by using area of effect powers to kill hidden enemies until the final cutscene triggers.